GEOLOGY 101 - The “Sailing Stones” of Death Valley: How a Mystery was Resolved

It was a mystery long in resolving, namely, the “sailing stones” of California’s Death Valley National Park. Sometimes called “walking rocks,” these are boulders as heavy as 100 pounds with one as large as 700 pounds. So, what was the mystery?

Death Valley has a sunbaked lake bed of cracked mud that is flat, flat, flat, and normally bone dry. Yet, dotting the valley floor are boulders with long grooves behind them cutting through the dried mud. Those grooves indicate such stones have scuttled along the valley floor, sometimes in parallel to one another. This has led some to refer to this area as the “Death Valley race track” or “Racetrack Playa,” with boulders racing one another toward some finish line.